Oil-burning furnace with baffles mounted therein



Jan. 30, 1951 J. N. WRIGHT 2,539,528

OIL BURNING FURNACE WITH BAFFLES MOUNTED THEREIN Filed May 4, 1946 Patented Jan. 30, 1951 EFICE OIL-BURNING FURNACE WITH BAFFLES MOUNTED THEREIN John N. Wright, Weston, Ontario, Canada Applicationlvlay 4, 1946-, SerialNo. 667,412

This invention relates to a fixture for coal burning furnaces which have been converted to burn oil.

When furnaces of this type are converted to burn oil it is usual to spray a mixture of fuel oil and air under pressure from a horizontally disposed nozzle into the bottom of the firing chamber. This mixture is ignited by electrodes and burns uncontrolled within the firing chamber. some of it burns in the centre of the chamber, some at the sides, some at the bottom and some at the top. In certain cases some of the fuel oil may not burn until it reaches the smoke pipe.

The air or water to be heated by the furnace surrounds or jackets the Walls of the fire pot and is introduced near the bottom and travels to the top thereof. It will be apparent that best heating efficiency will be obtained with such a furnace if the fuel oil burns and. releases its heat energy close to the walls of the firing chamber and adjacent the bottom of the furnace. This best condition is far from being attained in the usual coal burning furnace when it is converted to burn oil. As indicated above a large per" centage of the oil burns and releases its heat energy near the top and in the centre of the furnace. A great amount of this heat energy passes out the chimney before it has an opportunity to transfer to the water or air jacket surrounding the firing chamber and its heating value is lost. This invention effectively remedies this condition and causes the fuel oil to burn close to the walls of the firing chamber adjacent its bottom.

It is therefore an object of this invention to provide a fixture for an oil burning furnace in which the fuel is forced in to the firing chamber under pressure designed to cause the fuel to burn close to the walls of the firing chamber and adjacent to its bottom.

It is also an object of this invention to produce a fixture of the above general type which is cheap to manufacture and easy to install.

It is also an object of this inventionto provide a fixture of the above general class which will improve the general operation of an oil burning furnace.

With these and other objects in view the invention generally comprises a tubular member made from a refractory material and rigidly mounted in the lower part of the firing chamber of the furnace to define an annular space between it and the walls of the firepot. A planar disk-shaped baffle is mounted on the tubular member and projects into the annular space he- 2 Claims. (Cl. 1 58--4) tween the tubular member and the firepot walls. A nozzle directs a spray of oil into the annular space against the tubular member and baffle so that it will be reflected from one to the other until it has completely burned and released all of its heat energy. The combustion of the oil takes place entirely within the annular space at the bottom of the furnace and a maximum amount of the heat energy so released is transferred to the surrounding jacket of air or water before the products of combustion travel up the chimney.

The invention will be clearly understood by reference to the following detailed specification taken in conjunction with the drawings.

In the drawings:

Fig. 1 shows a front perspective view, partly broken away, of an oil burning furnace having the fixture of this invention mounted in its firing chamber.

Fig. 2 shows a perspective view of a preferred form of mounting plate for the tubular member having provision for more than one oil nozzle.

Fig. 3 is a plan view of the tubular member showing a preferred form of construction.

Fig. 4.- is a plan View of the disk-shaped bafiie showing a preferred form of construction.

Referring to the drawings and in particular to Fig. 1, I 1! indicates a conventional hot air coal furnace which has been converted to burn Oil. Cold air is introduced to this furnace by the cold air pipe ll adjacent its base and travels up the annular space [2 between the firepot l3 andthe casing l3a. As the cold air travels up the space I2 it becomes heated as a result of its contact with the hot walls [3 of the firepot or firing chamber l4 before it finally travels to the rooms to be heated by way of the pipes l5, IS.

The products of combustion in a furnace of this type escape through a chimney pipe (not shown) communicating with the upper part of the firing chamber [4. It will'be apparent that the heating efficiency of such a furnace will increase as the amount of heat that is transferred from the products of combustionto thecirculating air in the space 12 before they reach the chimney is increased. Once the hot gases enter the chimney their heating value is lost. In order to get the maximum heating efiiciency from burning oil it is desirable to cause the oil to burn adjacent the walls and near the bottom of the firepot. Byeifecting' such a combustion of the fuel the incoming cold air to the space 12 is immediately in communication with the newly formed. hot products of combustion through the firepot walls and has a maximum time of communication with them before they escape up the chimney. Obviously as the time of contact between the hot gases and the cold air increases the amount of heat transfer and hence efliciency will increase.

The letter A generally indicates a fixture for controlling the combustion of oil in a furnace as indicated above. The fixture preferably comprises a tubular deflector member I! rigidly mounted on a mounting plate 18 to define an annular space [9 between said tubular member and the walls of the firing chamber in the lower part of the furnace. The mounting plate I8 preferably includes a metal bottom plate l8 with a thick layer of a fire cement 20 such as castsette applied over it. The metal plate I8 is supported by transverse metal straps 2| which in turn are suspended from suitable standards 22 designed to rest on the base of the furnace. When the cement 28 is applied to the plate it seals off the actual firing chamber M from the lower portion 23 of the firepot. The standards are preferably of such length that the mounting plate is is on a level adjacent the upper part of the cold air inlet I I.

A bafile 24 is mounted on top of the tubular member and projects into the annular space l9 so as to leave a restricted passage 25 between it and the walls of the firing chamber to allow the products of combustion to pass through the firing chamber to the chimney.

The mounting plate I8 is formed with a hole 26 to admit the mount of the draft tube 2'? of a standard oil burner 21' The draft tube 21 is a conventional draft tube which houses the fuel atomizing unit 28 and electrode points 29 and also supplies a flow of air. It is preferably held in position by a bracket 21 secured to the straps 2 l.

In operation fuel oil is sprayed into the annular space H? against the tubular member ll under pressure by the atomizing unit 28 and is ignited by the electrode points 29. Some of the flaming oil is reflected from the tubular member against the baffle 24 and back down into the annular space [9, and some of it rolls around the tubular member within the annular space l9. It will be apparent that the fuel oil completely burns within the restricted annular space l9 and a very intense heat from the restricted combustion will be created therein. After the oil has completely burned the products of combustion can escape through the chimney by way of the restricted passage 25.

A large amount of the intense heat in the annular space I9 is transferred through the walls of the firepot E3 to the cold air entering the furnace by the pipe H. Further heat is trans- "ferred from the hot products of combustion to the air in the annular space l2 as the hot gases from the combustion travel towards the chimney so that by the time the products of combustion reach the chimney most of the valuable heat has been removed from them.

A plan View of a preferred construction for the tubular member I'i is shown in Fig. 3. It comprises four sections I! held together by a tongue and groove joints 3!} extending the length thereof. They are made from fireb'rick and rest on the mounting plate l8 by their own weight.

The bafiie 24 is shown in plan in Fig. 4. It preferably has an annular shape and is made from firebrick, and includes two sections 2 1 held in alignment by the interlocking tongued joints 3|.

5 :An alternative burner arrangement'is indicated in Fig. 2. The drawing shows only the mounting plate [8 and the burner draft tubes. In this embodiment three equally spaced apart holes 32 are made in the mounting member I8, each to admit a branch draft tube 33 of the main draft tube 21 to the annular space l9. Each branch tube 33 is rigidly secured to the straps 26 by brackets 34. In operation oil is sprayed into the annular space [9 from all three draft tubes at the same time in a similar manner to that explained in connection with Fig. 1 so that the amount of burning oil is substantially the same at all points within the annular space.

The deflector member I! and the baffle 24 are preferably made from a refractory material capable of absorbing a considerable amount of heat. If this isdone these members will take in quantities of heat when the oil burner is operating, which heat will be radiated to keep the furnace warm When the thermostat turns the burneroff so that when the burner starts up again it will not have to heat the furnace from a cold start. A more even heat is obtained in this way because the effect of the burner going on is felt in the room above in a shorter interval of time.

From the foregoing it will be apparent that I have produced an oil burner in which the combustion of the fuel oil is effected at the lower portion of the firing chamber close to the walls thereof. With this furnace it is not necessary to heat a large firing chamber volume in order to heat the air jacket and a greater percentage of the heat energy is recovered from the burning oil for useful heating purposes than in the conventional oil burner. It is thus possible to heat a house in a shorter period of time from a cold start and to heat it more efiiciently. I

In applying for Letters Patent I do not wish to be restricted to the specific form of the invention described above. Numerous changes could be effected without departing from the spirit of this invention. For example, the tubular member I! could extend substantially the length of the firing chamber, or an improved operation over the conventional furnace would be obtained even if the baffle 25 were omitted. Moreover, while this invention was primarily designed for converted coal burning furnaces it will be apparent that an on burning furnace could be designed to embody this invention.

What I claim as my invention is:

1. An oil burning furnace having a combustion chamber, a horizontal platform mounted adjacent the bottom of said combustion chamber with its marginal edges in sealed relation with the side walls of said combustion chamber, a column shaped deflector having a horizontal cross section with a perimeter less than the perimeter of said platform centrally mounted onone of its ends upon said platform, a high pressure atomizing fuel oil feed nozzle having its atomizing mouth located to direct the oil output therefrom against said deflector member, a baffle member, theperimeter of which is greater than the perimeter of a horizontal cross section of said deflector and less than the perimeter of said platform, said baflie being centrally mounted on the top end of said deflector to overlie the space defined between the vertical side walls'of said combustion chamber and the side walls of said deflector member'and to provide an annular space between its marginal edges and the sides of said combustion chamber through which the products of combustion from oil can pass after the oil has been burned beneath said baffle.

2. An oil burning furnace as claimed in claim 1 in which said column shaped member has a circular horizontal cross section and in which said 5 bafiie extends radially.

JOHN N. WRIGHT.

REFERENCES CITED The following references are of record in the 10 file of this patent:

Number 6 UNITED STATES PATENTS Name Date Best June 1, 1915 Walker et a1 Oct. 30, 1917 Schrader Apr. 24, 1928 Hussey May 18, 1937 Pirich Nov. 23, 1937 Harvey Dec. 16, 1941 Pollock Dec. 8, 1942 

